So I have encountered this problem as well, and after addressing at the Apple "Genius" Bar, for an hour, to no avail, I have found out sort of a solution.
It seems that some of the "events" in my Calendar were scheduled under "Atlantic Time" (AST) instead of Eastern Standard Time (EST). Atlantic Time does not use Daylight Savings Time, and since the main Calendar was setup at Eastern Standard Time (EST) it knocked my appointments from now till we Spring Forward, out of wack by an hour.
So the, disappointing fix, it is a little better than re-entering all the events.
If you select the event, and press (apple I), you will get an info dialogue box. In this box, go to the "time zone" drop down menu, and make sure that the "event time zone" is the same as your "iCal's time zone." ICal will ask you if you want to change this repeating event, select "all future events."
So by fixing the first week, all following weeks should be in line.